Áp dụng DSP lập trình trong truyền thông di động P11

Increased bandwidth for Third Generation (3G) communication not only expands the capacity to support more users, but also makes it possible for network providers to offer new services with higher bit rates for multimedia applications. With increased bit rates and programmable DSPs, several new types of applications are possible for mobile devices, that include audio and video content. No longer will there be a limited 8–13 kbps, suitable only for compressed speech. At higher bit rates, the same phone’s speakers and DSP with different software can be used as a digital radio | The Application of Programmable DSPs in Mobile Communications Edited by Alan Gatherer and Edgar Ausländer Copyright 2002 John Wiley Sons Ltd ISBNs 0-471-48643-4 Hardback 0-470-84590-2 Electronic 11 Video and Audio Coding for Mobile Applications Jennifer Webb and Chuck Lueck Introduction Increased bandwidth for Third Generation 3G communication not only expands the capacity to support more users but also makes it possible for network providers to offer new services with higher bit rates for multimedia applications. With increased bit rates and programmable DSPs several new types of applications are possible for mobile devices that include audio and video content. No longer will there be a limited 8-13 kbps suitable only for compressed speech. At higher bit rates the same phone s speakers and DSP with different software can be used as a digital radio. 3G cellular standards will support bit rates up to 384 kbps outdoors and up to 2 Mbps indoors. Other new higher-rate indoor wireless technologies such as Bluetooth WLAN and ultra wideband will also require low-power solutions. With low-power DSPs available to execute 100s of MIPS it will be possible to decode compressed video as well as graphics and images along with audio or speech. In addition to being used for spoken communication mobile devices may become multifunctional multimedia terminals. Even the higher 3G bit rates would not be sufficient for video and audio without efficient compression technology. For instance raw 24-bit color video at 30 fps and 640 X 480 pixels per frame requires 221 Mbps. Stereo CD with two 16-bit samples at kHz requires Mbps 1 . State-of-the-art compression technology makes it feasible to have mobile access to multimedia content probably at reduced resolution. Another enabler to multimedia communication is the standardization of compression algorithms to allow devices from different manufacturers to interoperate. Even so at this time multiple standards exist

Không thể tạo bản xem trước, hãy bấm tải xuống
TÀI LIỆU MỚI ĐĂNG
15    16    4    27-11-2024
Đã phát hiện trình chặn quảng cáo AdBlock
Trang web này phụ thuộc vào doanh thu từ số lần hiển thị quảng cáo để tồn tại. Vui lòng tắt trình chặn quảng cáo của bạn hoặc tạm dừng tính năng chặn quảng cáo cho trang web này.